Here in the USA if you asked me where the best place to go fishing is I would probably direct you to Florida. (I hear there is very good fishing down there!)Anyways In Japan is there a whole lot of fishing in general? Is there better fishing grounds in someplaces than in others?
The Reason why i ask is that I absolutely LOVE to fish and if I ever went to Japan I would make sure that was part of my trip.
Also I hear that in Japan when they go fishing they bring some sushi rice and soy sauce and if they catch anything they immediately make it into sushi and scarf it down.

I am not sure of great fishing sites, but you should check out the movie series 釣りバカ日誌 (Diary of a fool for Fishing) - kind of stupid, funny - but I really enjoy the series. They are simple stories which helps make it easy to understand.

As for where to get them. I am not sure. I have bought a few in Japan at used video stores. Check Ebay to see if anyone has tsuri baka nisshi (try different spellings too). We do have a few manga from the series at our store, but I think the movies are a lot better.